Transportation of goods at sea constitutes a significant source of air pollution and greatly influences the quality of air in many cities around the globe. According to research reports, health costs related to the treatment of diseases caused by ship traffic amount to some estimated 60 billion annually in Europe alone, corresponding to approximately 10% of all health costs associated with the effects of air pollution in the region. In Europe, emissions from vessels cause an estimated 50,000 premature deaths per year.
In order to reduce the environmental impact of ship traffic, the European Union and the International Maritime Organization have implemented regulations aimed at reducing emissions, in particular a reduction of the emissions of SO2 and NO2. Certain control areas, so-called Sulphur Emission Control Areas (SECAs), have been defined globally in which enhanced emission restrictions apply. When entering such areas, vessels are required to use low-emission fuel, whereas other and cheaper types of fuel may be used outside SECAs. Accordingly, most modern vessels are equipped with two fuel tanks, of which one holds SECA-compliant fuel and another one is for non-SECA-compliant fuel. Commonplace fuels include heavy fuel oil (HFO) having a sulphur concentration of about 2.5% and marine diesel oil (MDO) with a sulphur concentration of about 1% (after Jan. 1, 2015: 0.1%).
The adaptation of environmental regulations also increases the demand for national authorities' control of vessel emissions. However, no reliable and cost-efficient procedure for performing exhaust measurements of plumes of vessels has been developed so far. Accordingly, it has not been possible hitherto to efficiently control emissions of vessels, and it may be suspected that many vessels do not carry out the required shift to SECA-compliant fuel when entering SECAs. A need hence exists for new technologies which enable national and international maritime organizations to enforce environmental regulations.